As examples of edible water purifiers which have been widely used in home or office, there are tap water purifiers which filtrate city water with solid or organic materials using a plurality of purifying filters to supply clean water to users, hot and cold water purifiers which purify water and selectively cool or heat the purified water to supply edible water to the users, and hot and cold water generators on which large-sized water bottles containing therein raw water are put so that the raw water supplied from the large-sized water bottles into water tanks of the water generators is selectively cooled or heated for the users.
In the above-mentioned edible water purifiers, the tap water purifiers to be directly coupled to faucet pipes each include a base which has both a water feed hole and a clean water discharging hole, a cylindrical housing which is provided on an upper part of the base, a purifying filter which is provided in the housing, and a filter cartridge with a head provided on an upper part of the housing. The conventional tap water purifiers are individually coupled at the feed water hole thereof to a faucet pipe. Thus, the city water fed from the faucet pipe is purified by the plurality of purifying filters prior to being discharged through a clean water discharging hole to the outside.
However, with the passage of time, a great quantity of impurities are deposited on the purifying filters. Thus, the filtering abilities of the conventional water purifiers are deteriorated. Therefore, the conventional purifiers force the users to periodically change filter cartridges with new ones. Due to frequent replacements of the filter cartridges, the conventional water purifiers cause inconvenience to the users and impose additional expenses on the users.
The hot and cold water generators and the hot and cold water purifiers each include a water tank which has a structure enabling storage of raw water or clean water of about 10˜20 liters. Each of both the hot and cold water generator and the hot and cold water purifier draws thereinto air from the outside to smoothly discharge the water.
However, in each of both the conventional hot and cold water generator and the conventional hot and cold water purifier, the water contained in the water tank may be processes by passing through a purifying filter, which is not changed with a new one even after a predetermined period is passed. In the above state, the processed water may be polluted by the contaminated purifying filter used for the long period. Furthermore, even though the city water is processed by passing through a fresh purifying filter, or the raw water is sanitarily processed, the water contained in the water tank may be contaminated by various harmful bacilli, because the bacilli along with the air may be drawn into the water tank through an air inlet. Thus, the water discharged from the conventional water generators or purifiers may not be suitable for drinking. In case of the conventional hot and cold water generators, the user can observe a state of the contaminated water tank with the naked eye. Thus, the user can periodically clean the water tank or put a germicidal agent in the water tank However, in case of the conventional hot and cold water purifiers, the water tank is typically installed in a casing of the water purifier. Thus, most users use the water purifiers without cleaning the interiors of the water tanks before the purifying filters are changed with new ones. Therefore, the hot and cold water purifier used for a long period is more seriously contaminated by the bacilli. In the above state, the water, processed by the conventional hot and cold water purifier used for a long period, may be worse in quality by the bacilli than the water which is not purified, thereby the processed water may be bad for the health
In an effort to overcome the problem in that the water is contaminated by the bacilli, a technique in that an ultraviolet sterilizer is provided in the water tank of an edible water purifier to prevent the bacilli from being generated and propagated was proposed.
The conventional ultraviolet sterilizer includes a quartz tube with an UV (ultraviolet) lamp, a sleeve which has therein the quartz tube, a holder which fastens thereon both ends of the sleeve and supports thereon the quartz tube, and a housing which has therein the sleeve and provides both a water inlet and a water outlet. The conventional ultraviolet sterilizer can sterilize bacilli by ultraviolet rays having wavelengths of 254 mm, but is problematic as follows.
First, because the ultraviolet rays penetrate water to 1˜2 mm, only water, placed around an outer surface of the quartz tube having therein the UV lamp, is sterilized. Thus, the conventional ultraviolet sterilizer cannot sterilize the whole of the water contained in the water tank.
Second, the edible water purifier with the conventional ultraviolet sterilizer may supply water of a state, in which the water sterilized by the sterilizer is mixed with the water which is not sterilized, to the users. Thus, the user may be injured.
Third, in case that the water level in the water tank is low, the sterilizing ability of the ultraviolet sterilizer is deteriorated.
Fourth, the conventional ultraviolet sterilizer is problematic in that the ultraviolet rays cannot dissolve or eliminate various organic materials, such as environmental hormone, etc.